1) Some one who is more than a tool, They just keep adding more things to make them more of a tool.
2) Usually a girl, but not exclusively, who continually dates unsuitable people and hence bagstools. Therefore they are a toolbagger. I.e they are collecting tools.
3) An individual within the tool manufacturing industry whos job it is to bag the tools. E.G they must bag all the tools into a tool kit before sale to the public.

1) "hey Tony can you believe that guy? what a tool!"
"Dude he is a tool bagger"
2)"have you seen who Janice is going out with now. he is such a loser!"
"Yeah Janice is such a tool bagger"
3)"Hey man nice to meet you, what do you do?"
"Ah not much, by day i'm a tool bagger"